Intra-Abdominal Hypertension:

Author

Evidence that Early Detection and Management Improves Outcomes and Reduces Resource Utilisation

Introduction

There are several important issues concerning intra-abdominal hypertension
(IAH) and abdominal compartment syndrome (ACS). The first is that IAH/ACS are
often seen outside the trauma population. In fact this syndrome is just as
common in the medical ICU as the surgical ICU, with prevalence rates over 30%
in both populations (Malbrain et al. 2004). The second point is that clinically
important increases of intra-abdominal pressure (IAP) are possible in just a
few hours. For this reason, measurements conducted every 6-12 hours in the
unstable patient are likely inadequate due to the risk of delayed diagnosis and
prolonged tissue ischaemia (Balogh et al. 2003). Most importantly, however, it
must be noted that intra-abdominal pressure can greatly assist the clinician in
decisionmaking in the complex critically ill patient. A quickly increasing IAP
in a patient could point straight to the diagnosis of abdominal compartment
syndrome, rapidly identifying the underlying cause of multi-organ dysfunction.
This data could allow the timely reversal of the underlying cause, reversal of organ
ischaemia, prevention of permanent end organ damage and early transfer out of
the ICU – freeing up an ICU bed for another patient and reducing resource
consumption. The following discussion will focus on this concept – outcomeimpact and resource consumption
in patientswith IAH/ACS.

Intra-abdominal
Hypertension: Definitions and Risk Factors

International consensus definitions, risk factors, monitoring
and interventional recommendations for intra-abdominal hypertension were
published in early 2007 (Cheatham et al. 2007). Table 1 lists important
definitions. Risk factors for developing elevated intra-abdominal pressure are
listed in Table 2. All newly admitted ICU patients or those with new organ
dysfunction who have two or more risk factors should have serial
intra-abdominal pressure measurements taken to ensure IAH is not developing.

While epidemiologic data demonstrates a clear association
between IAH/ACS and morbidity, a common question is whether IAH/ACS is simply a
prognostic indicator or if it is a modifiable parameter that can be addressed
to improve patient outcomes. Increasing data suggests the latter. Ten years
ago, Ivatury and colleagues noted that interventions directed specifically at
preventing ACS in trauma patients undergoing damage control laparotomy (i.e.
using temporary abdominal closure following the initial laparotomy) resulted in
marked improvement in survival (89% vs. 61%) (Ivatury et al.1998).

Since that publication other institutions have implemented temporary
abdominal closure protocols with clear outcome improvements (Cipolla et al. 2005;
Cheatham and Safcsak 2007). This advancement is now commonly applied in field
hospitals in the ongoing Iraq war and may explain some of the dramatic
improvements in survival from severe trauma in this war compared to the gulf
war 15 years prior. Other surgical subspecialties caring for abdominal aortic
rupture, neuro-trauma and severe pancreatitis also report outcome improvements using
selected TAC as an interventional therapy for IAH (Oelschlager et al. 1997;
Joseph et al. 2004; Leppaniemi et al. 2007). Most recently, Cheatham et al
presented data outlining outcomes and resource utilisation in patients with ACS
who were treated with temporary abdominal closure plus a standardised medical
interventional protocol (Cheatham and Safcsak 2007). Utilising this protocol, the
investigators noted

• a reduction in mortality (49% down to 29%),

• more rapid and more successful closure of the abdominal wall
(34% vs. 61%),

• reduced total hospital LOS (29 days down to 18 days) and

• decreased resource utilisation.

The authors conclude that evidence based IAH/ACS management
strategies significantly improve patient survival without an increase in resource
utilisation and should be adopted by other institutions.

Non-surgical patients with secondary IAH/ACS also demonstrate
outcome improvements with early interventional therapy. Oda established a
protocol whereby all patients with severe acute pancreatitis who developed IAP
>15 mm Hg underwent continuous renal replacement therapy before onset of
organ dysfunction (Oda et al. 2005). The result was a rapid reduction in IAP
levels to less than 10 mm Hg, along with a drop in serum cytokine levels.
Compared to their traditional 30% ICU mortalities for this patient population,
this interventional group had a mortality of 6%. Sun also studied severe
pancreatitis patients, randomising them into a study arm that received IAP monitoring
plus peritoneal drainage with a continuous indwelling catheter versus no IAP
monitoring and no catheter (Sun et al. 2006). All patients were otherwise
managed in the same fashion. Groups were compared for changes in APACHE II
scores, hospital LOS and survival to discharge. The interventional arm fared
much better – APACHE II scores dropped while hospital LOS and mortality were
cut in half (15 d vs. 28 d, 10% mortality vs. 20% mortality).

Conclusion

Similar to compartment syndromes of the extremity or skull,
prolonged elevation of pressure in the abdominal compartment leads to severe
tissue ischaemia and irreversible cellular death. Without treatment, long ICU
admissions, progressive organ failure and death may ensue. Current evidence suggests
that early compartment pressure monitoring combined with interventional
therapies can reduce morbidity and mortality while simultaneously reducing
total resource consumption by the patient. Intensivists should consider intra-abdominal
pressure as one piece of the physiologic picture and begin implementing an approach
to managing this syndrome in the appropriate patient populations.

Assessment and management protocols are available
online at www.wsacs.org, while teaching materials and nursing management protocols
can be found at www.abdominalcompartment-
syndrome.org.

No comment

Highlighted Products

NovaPort cannulas are designed specially to meet the needs of extracorporeal lung and heart support circuits and perioperative perfusion in minimally invasive heart surgery.All blood-contact surfaces of the NovaPort cannulas are coated with the bio- and...

FeaturesMindray BeneVision Central Monitoring System is a powerful and scalable solution providing for continuous, real-time surveillance across networks large and small. The system can display patient information from networked monitors, wireless transport...

The iLA Membrane Ventilator is an extrapulmonary ventilation system which is used primarily to remove carbon dioxide. The heart pumps blood through it as it does through a natural organ. The gas exchange takes place via a plasma-tight, heparin-coated...

The technical and clinical reference standard for all B·R·A·H·M·S PCT assays.
All clinical cut-offs and algorithms were developed based on B·R·A·H·M·S PCT sensitive KRYPTOR.
Homogeneous immunoassay for the quantitative d

Always in sight, always in mind
Features
Mindray believes the best way to predict the future is to create it. The revolutionary BeneVision N22/N19 is designed to optimize user experience by satisfying all your clinical demands. With visionary-stimulating...